Automatic test tube transporter and sample dispenser having solid state controls

ABSTRACT

An automatically controlled test tube transporter apparatus which advances a test tube rack containing two rows of receptacles for test tubes under a vertically movable aspirating and dispensing tip or nozzle which is adapted to move down into adjacent tubes and aspirate or discharge depending on the test to be performed. The tip is operationally in communication with a twin pipette metering and dispensing apparatus which includes a linearly adjustable eccentric mechanism which drives the pipette pistons with a motion of adjustable sinusoidal amplitude. The apparatus includes a solid state control circuit which includes a binary shift register. The pipettes may be adjusted to either work in parallel or alternating strokes. An automatic tip wiping mechanism, controlled by the operation of the tip, is provided to insure precision in the processing. The apparatus is adapted to be set for continuous operation or for individual test tube processing cycle operation. Empty racks can be advanced without engaging the tip and pump apparatus. The pipetting mechanism may be operated separately without the operation of the transporting mechanism. A malfunction and alarm logic circuit gives a warning in case of certain malfunctions and stops the apparatus.

United States Patent [191 Downing et al.

111 3,753,657 Aug. 21, 1973 1 AUTOMATIC TEST TUBE TRANSPORTER AND SAMPLE DISPENSER HAVING SOLID STATE CONTROLS [75] Inventors: Harvey T. Downing, Huntsville;

Charles V. Lawson, Arab; Byron E. Sturgis, Huntsville, all of Ala.

[73] Assignee: Micromedic Systems, Inc.,

Philadelphia, Pa.

[22] Filed: June 11, 1971 [21] Appl. No.: 152,189

[52] US. Cl 23/253 R, 23/259, 73/425.6, 141/130 [51] Int. Cl. G0ln 21/00 [58] Field of Search 23/230, 253, 292, 23/259; 141/130 [56] References Cited UNITED STATES PATENTS 3,143,393 8/1964 DeSeguin Des Hons 23/259 X 3,197,285 7/1965 Rosen 23/259 X 3,327,535 6/1967 Sequeira 23/259 X 3,413,097 11/1968 Jungner 23/259 X 3,576,605 4/1971 Drake et al. 23/259 3,622,279 11/1971 Moran '23/259 3,687,632 8/1972 Natelson 23/259 UP? g 20 2o i'ilff 2i l8 '1 g I T l'l Primary Examiner-Morris O. Wolk Assistant Examiner--R. E. Serwin Attorney-Gerry J. Elman et al.

[5 7] ABSTRACT An automatically controlled test tube transporter apparatus which advances a test tube rack containing two rows of receptacles for test tubes under a vertically movable aspirating and dispensing tip or nozzle which is adapted to move down into adjacent tubes and aspirate or discharge depending on the test to be performed. The tip is operationally in communication with a twin pipette metering and dispensing apparatus which includes a linearly adjustable eccentric mechanism which drives the pipette pistons with a motion of adjustable sinusoidal amplitude. The apparatus includes a solid state control circuit which includes a binary shift register. The pipettes may be adjusted to either work in parallel or alternating strokes. An automatic tip wiping mechanism, controlled by the operation of the tip, is provided to insure precision in the processing. The apparatus is adapted to be set for continuous operation or for individual test tube processing cycle operation. Empty racks can be advanced without engaging the tip and pump apparatus. The pipetting mechanism may be operated separately without the operation of the transporting mechanism. A malfunction andalarm logic circuit gives a warning in case of certain malfunctions and stops the apparatus.

48 Claims, 36 Drawing Figures Patented Aug. 21, 1973 R 3,753,657

22 Sheets-Sheet 1 INVENTOR HARVEY 7f DOWN/N6 CHARLES LAWSON, BYRON E. STURGIS H 9 LL ATTORNEX} Patented Aug. 21, 1973 22 Sheets-Sheet 2 Patented Aug. 21, 1973 3,753,657

22 Sheets-Sheet 5 FIG Patented Aug; 21, 1973 22 Sheets-Sheet 4.

Patented Aug. 21, 1973 22 Sheets-Sheet 5 Patented Aug. 21, 1973 22 Sheets-Sheet 6 Patented Aug. 21, 1973 22 Sheets-Sheet '7 mmm 0mm llmn wwm Patented Aug. 21, 1973 22 Sheets-Sheet 9 .mmm

Patented Aug. 21, 1973 22 Sheets-Sheet 12 Patented Aug. 21, 1973 22 Sheets-Sheet l5 .954 Jmmh Omh mmh wmw 5% mm bow Patented Aug. 21, 1973 22 Sheets-Sheet 15 mmm Nmm

wk EN Nwh Ow. mi. @vh 9 at Patented Aug. 21, 1973 22 Sheets-Sheet l 9 FIG 29 

2. An apparatus as in claim 1 wherein said tip-shifting means includes a driven grooved cylindrical cam means and a cam groove follower means adapted to ride in a groove of the cam means to control the position of said tip means.
 3. An apparatus according to claim 2 in which the cylindrical cam means has two peripheral cam grooves and the follower means comprises a separate follower for each cam groove and a snap-action lever, connected at each of its ends to a separate one of the followers, for alternately bringing a follower into its respective groove, each groove having a portion which raises the follower therein and rocks the lever to its snap-action position, thereby causing the other follower to engage the other groove.
 4. An apparatus as in claim 3 including a bidirectional tip motor, said control means adapted to rotate said motor in either direction, one direction of rotation adapted to move said tip downwardly and the other direction of rotation adapted to move said tip upwardly.
 5. An apparatus as in claim 4 and further including a switch cam having a pair of lobes located adjacent said cylindrical cam, said cylindrical cam having an actuator bar thereon which is adapted to engage one of said lobes upon rotation in either direction.
 6. An apparatus as in claim 1 wherein said tip-moving means includes a pair of guide rods and a cam means to move said guide rods longitudinally to a first and second position, tip holder means mounted on said guide rods, said tip means being located in said tip holder means, and a cross slide assembly means associated with said tip holder to move said tip holder and said tip means down and up along said guide in both said positions.
 7. An apparatus as in claim 6 and including a drive means for rotating said cam means, a crank means associated with said drive means and operatively in engagement with said cross slide means to effect downward and upward displacement of said cross slide means and said tip holder when said cam means is rotated.
 8. An apparatus as in claim 7 and including a cam follower toggle means, said toggle means having two cam followers and said cam having two cam grooves therein, said toggle means adapted to toggle when one of said cam followers rides out of one of said cam grooves and thus to force the remaining cam follower into the other cam groove.
 9. An apparatus as in claim 7 wherein said crank means has a top dead center cam on one end thereof, a switch means, said top dead center cam means adapted to engage said switch means when said cross slide assembly and said tip holder are in a predetermined positIon for either aspirating or dispensing.
 10. An apparatus as in claim 1, and including a rack bar means adapted to bias said racks into advancement position on said surface means.
 11. An apparatus as in claim 1 wherein said liquid sampling and dispensing means comprises a pair of pump units, each pump unit having a piston and a common driving means for driving the pistons of each said pump unit in a sinusoidal reciprocal manner, each pump unit having at least two port bores thereon and valve means associated with said common driving means and said port bores to alternately place the chamber of each pump unit in communication with one of said port bores respectively.
 12. An apparatus as in claim 1 and additionally including means for wiping said tip means as it is moved upwardly by said tip raising and lowering means in each position.
 13. An apparatus as in claim 12 wherein said wiper means includes a supply reel of wiper tape and a take-up reel for the wiper tape and a driving spool means for advancing the wiper tape.
 14. An apparatus as in claim 13 wherein said tip wiper means also includes a pair of pad means and means to press said wiper tape against the sides of said tip means as it is being raised in either position to effect a wiping thereof.
 15. An apparatus as in claim 13 wherein said wiper spool driving means includes a plurality of peripheral projections adapted to penetrate said wiper tape.
 16. An apparatus as in claim 12 including a drive means for operatively effecting rotation of said wiper spool drive means upon upward motion of said tip means.
 17. An apparatus as in claim 1 wherein said control means includes a malfunction and alarm circuit means, said malfunction alarm circuit means including a buzzer which is adapted to sound for a predetermined period of time upon the completion of processing and then remain silent for a second period of time and again sound for said first predetermined period of time whereby said cycle is repeated until an operator shuts off the apparatus.
 18. An apparatus as claimed in claim 1 including wiper means for wiping said tip during its upward movement out of said tubes, said wiper means including a supply reel of wiping tape, and said control means having a circuit means to prevent said apparatus from functioning if there is no supply reel in place.
 19. An apparatus as in claim 1 and including wiper means to wipe said tip, said wiper means being mounted on a tray or drawer which may be pulled outwardly from the apparatus into open position for servicing, said control means including a malfunction circuitry means adapted to shut down the operation of the machine if the tray is in open position or if a jam occurs in the rack advancement means.
 20. An apparatus as in claim 19 wherein said wiper means includes a reel supply of tape, and said control means has a photoelectric means which gives a signal to the operator if the supply of tape is low.
 21. An apparatus as in claim 1 wherein said control means includes automatic switches for sensing the presence of a rack, sensing the condition of the tip being raised, sensing the presence of tubes on both rows on said rack tray, and sensing when said rack is through being porcessed.
 22. An apparatus as in claim 21 wherein said control means additionally includes means for providing an ejection pulse, an ejection apparatus, said ejection pulse operating to allow said ejection apparatus to eject a processed rack onto said surface means.
 23. An apparatus as in claim 1 wherein said control means has circuitry providing for an automatic mode wherein said tubes are sequentially processed and the rack advanced incrementally.
 24. An apparatus as in claim 23 wherein said control means additionally includes a manual mode circuit by which an operator can perform one sampling and dispensing apparatus at a time.
 25. An apparatus as in claim 24 wherein said control means also includes an advance mode circuit and means to advance continually the rack withOut allowing the pipette and tip means to process any of the tubes contained therein.
 26. An apparatus as in claim 25 wherein said control means additionally includes a pipette mode circuit means adapted to allow an operator to operate the pipette without operating the tip or liquid sampling and dispensing means.
 27. An apparatus as in claim 26 wherein said control means has an exclusionary circuit means allowing only one of said modes to be operated at a single time.
 28. An apparatus as in claim 1 wherein said control means includes circuit means adapted to prevent processing or operation of the apparatus before the rack is in a correct position, the pipette is in correct pumping sequence, before and when there is no malfunction signal present.
 29. An apparatus as in claim 1 wherein said control mans includes an advance circuit means which will advance the rack until tubes are sensed by said control, means, this allowing for a partially filled rack to be processed.
 30. An apparatus as in claim 1 wherein said control means includes a binary shift register and solid state controls, the shift register acting to automatically operate the control means to provide a predetermined sequence of operation with appropriate times and time delays therebetween.
 31. An apparatus as in claim 30 wherein said control mans includes a START switch means which is adapted, upon being held in depressed condition, to provide automatic processing and stepping of said shift register.
 32. An apparatus as in claim 1 wherein said tip raising and lowering means includes a tip motor means, the length of time of rotation of said motor in either direction controlling the depth of stroke of said tip means, said control means providing that rotation of said motor means in one direction allows said tip to move downwardly in both front and rear positions and rotation of said motor in an opposite direction allows said tip to move upwardly in both front and rear positions.
 33. An apparatus as in claim 32 wherein said control means has manually adjustable timer means to control the amount of rotation of said motor means in either direction, thereby determining the depth of stroke of said tip means in both said positions.
 34. An apparatus as in claim 32 wherein said control means includes a circuit means adapted to first reverse said motor means, provide a predetermined delay period to allow the dynamic braking of said motor to take effect, switch the contacts on said motor, provide a second time delay of a predetermined amount of time and finally to start said motor rotating in an opposite direction.
 35. An apparatus as in claim 1 wherein said control means has an external select switch adapted to allow an operator to control the operation of the transporter externally, said control means also having an external potentiometer means, said control means including two timing means, said first timing means adapted to provide a delay to allow the reagent to mix with a sample after it has been dispensed above the level of the sample in the tube and said second timing means adapted to provide a pulse to said tip raising and lowering means to move the tip down below the level of said mixed reagent and sample in the same tube, said potentiometer providing adjustment ot said timer whereby an operator may select the depth of additional stroke which the tip moves down into said tube.
 36. An apparatus as in claim 1 wherein said liquid sampling and dispensing means includes a control circuit, said control circuit, when activated, providing power to said control means for the entire apparatus.
 37. An apparatus as in claim 1 wherein said control means includes circuit means to operate an auxiliary pipette or liquid sampling and dispensing means which can be used in conjunction with said liquid sampling and dispensing means.
 38. An apparatus as in claim 37 wherein an auxiliary pipette is provided on said liquid sampling and dispensing means and is attached thereto in fixed positiOn so as to be in a position to dispense into the tubes in one row on said rack.
 39. In an apparatus for transferring liquids with respect to containers, especially test tubes, comprising a base, means for incrementally moving a holder or rack having a plurality of receptacles for the containers longitudinally along a path over the base from an initial station to a final station, a movable nozzle or ''''tip'''' above an intermediate station along the path, positive-displacement pump means comprising a piston reciprocable in a cylinder having a port for passage of liquid, a flexible conduit connecting the port with the tip for communication therewith, means for moving the tip relative to the base, and control means for coordinating the operation of the several means, the improvement wherein: the rack has two rows of receptacles for the containers extending longitudinally of the rack, the means for moving the tip comprises (1) means for moving it back and forth transversely of the rows from a position over a receptacle in one row of the rack to a position over a receptacle in another row of the rack and (2) means for lowering and raising the tip in each of its positions, and the control means is constructed and arranged to perform one or more cycles, each cycle including the following steps in the order recited: the rack is advanced in its path to bring a receptacle in one of the rows under the tip, at which time the rack-advancement-ceases, the tip is moved down into the container under the tip, the piston is moved through one of its alternate strokes while the tip is in the container, the tip is raised out of the container, the tip is moved transversely of the rack to a position over a receptacle in the other row, the tip is lowered into the container under the tip, the piston is moved through the other of its alternate strokes, the tip is raised out of the container, and the tip is moved transversely back to a position over the first row.
 40. In an apparatus for transferring liquids with respect to containers, especially test tubes, comprising a base, means for intermittently moving a test tube holder or rack longitudinally along a path over the base from an initial station to a final station, a movable aspirating and dispensing tip above an intermediate station along the path, positive displacement pump means comprising a piston reciprocable in a cylinder having a port for inlet and outlet of liquid, a flexible conduit conecting the port with the tip, means for lowering and raising the tip relative to the base, and control means for coordinating the operation of the several means, the improvement wherein: the apparatus also comprises means for wiping the tip comprising a rotatable reel carrying a wound supply of an absorbent wiping material in the form of a tape of indefinite length, a driven take-up reel for the tape, means for guiding the tape from the supply reel to the take-up reel along a path adjacent the path of the tip, and means for pressing the tape into wiping engagement with the tip whenever the latter rises.
 41. In an apparatus for transferring liquid with respect to containers, especially test tubes, comprising a nozzle, a plurality of receptacles, pump means, a flexible conduit connecting the pump means to the nozzle for communication therebetween, means for moving, relative to one another, the nozzle and the receptacles including means for raising and lowering the nozzle in a path relative to the receptacles, the improvement wherein there is provided nozzle-wiping means comprising a rotatable reel carrying a wound supply of absorbent wiping material in the form of a tape of indefinite length, a driven take-up reel for the tape, means for guiding the tape from the supply reel to the take-up reel along a path adjacent the path of the nozzle, and means for pressing the tape into wiping engagment with the nozzle.
 42. Apparatus according to claim 41 comprising means for actuating the pressing means in response to upward movement of the nozzle.
 43. In an apparatus for transferring liquids with respect to containers, especially test tubes, comprising a rack having a plurality of receptacles for supporting containers therein, a nozzle, means for intermittently moving the rack to position the receptacles successively under the nozzle, pump means, and a flexible conduit connected to the pump means and the nozzle to provide fluid intercommunication therebetween, an improved nozzle module unit comprising a support, stationary, vertically extending guide rods secured to the support, a cross-head slidably mounted for motion up and down on the guide rods, a rotatable crank arm having a roller secured thereto and projecting into a guideway in the cross-head, means for rotating the crank arm, and means secured to the cross-head for supporting the nozzle to move it up and down with the cross-head.
 44. Apparatus according to claim 42 in which the nozzle module unit also comprises a pair of guide bars inclined to both vertical and horizontal and the nozzle-supporting means is a holder slidable up and down the guide bars.
 45. Apparatus according to claim 52 in which the nozzle module unit also comprises a pair of normally spaced-apart sponge rubber pads and means for moving the pads towards each other and gainst the nozzle as it moves upwardly.
 46. Apparatus according to claim 42 in which the nozzle module unit also comprises a pair of guide bars inclined to both vertical and horizontal and the nozzle-supporting means is a holder slidable up and down the guide bars, and the module unit also comprises a pair of sponge rubber pads, mounted on rods slidable transversely with respect to the lower ends of the inclined guide bars, spring means for normally holding the pads in an opposed but spaced relationship with each other, and means for urging the pads together against the nozzle when the nozzle moves upwardly.
 47. Apparatus according to claim 46 which also comprises means for shifting the inclined guide bars back and forth between two positions so that lowering of the nozzle holder lowers the nozzle into different containers supported in the receptacles of the rack under the two positions and the means for urging the pads together is effective to press them against the nozzle in both positions.
 48. Apparatus according to claim 47 in which the means for urging the pads against the nozzle comprises a pair of arms pivotally mounted on parallel horizontal axes and rotatable cam means for swinging the arms on their pivotal axes. 